Dienstag, 23. Juni 2020

kcbench, the Linux kernel compile benchmark, version 0.9.0 is out

Hello, is this thing still on? Looks like I have not blogged here in nearly 10 years. Uhhps. But today there is a reason to write something again:

I released kcbench 0.9.0. Kcbench is a simple Linux kernel compile benchmark that downloads the Linux sources and measures the time it takes to build the kernel. This is how it looks:

One can use the benchmark to compare different machines, just make sure they use a similar compiler. Kcbench can perform stress tests, too. It's also useful to find the optimal number of jobs for compiling source code, as 'just use all cores' sometimes is not the fastest setting.

For example, on a AMD Ryzen Threadripper 3990X (64 cores/128 threads) a lot of people will expect compiling with 128 jobs (`make -j 128`) will be fastest. But while testing kcbench on a such a processor it turned out that at least the testes machine built a Linux kernel quite a bit faster with only 64 jobs (and thus utilizing only the real cores):

There was no time for a closer inspection, but it looks like memory and its caches might have been a bottleneck that lead to this. It was different on a AMD EPYC 7742 (128 cores/256 threads), as using 256 jobs there lead to the best result:
For more about kcbench see the project page at gitlab, the README and the man-pages for kcbench and kcbenchrate. The rate variant is one of the big new enhancements in the new version. Instead of compiling one kernel really fast kcbenchrate compiles one kernel on each CPU to measure the rate and keep the all cores busy all the time. See the man-pages for a more detailed explanation of the approaches the two use. Cross-compilation is supported now, too. To learn about all the other improvements in kcbench v0.9.0 see its release page.

The new kcbench including kcbenchrate is in Fedora Rawhide. It's also in updates-testing for Fedora 31 and Fedora 32 currently and will be moved to the proper updates repositories in a few days.

Samstag, 16. Juli 2011

Why I'm not posting much on Google+ – or – My big problem with Google+

The "tldr"-version: Google+ has lots of nice things, but in its current state it does not look like a solution that could replace twitter (and identi.ca) for me at all. In fact I'd need something like tags or topic-streams (that people could select when adding me to their circles) for my messages before I'd feel more comfortable to write public posts on G+ more that occasional.

The detailed version: It seems the people that added me to their circles mainly know me from one of four aspects of my life:
  1. my work for heise.de and c't
  2. English translations of that work published on "The H"
  3. my contributions to Fedora
  4. this strange thing called real-life (good 3D effects!)
Sending out just one public information stream to those people afaics would only make very few of them happy; I'd feel like spamming them with crap they are clearly not interested in.

Among the reasons for that view are simple language problems: I was born and live in Germany and speak German most of the time – but I know lots of people from the US, the UK and other countries and most of them do not know more that five German words. Many of them added me to their circles nevertheless; I'm also in a lot of circles where I don't know the people at all; hence I don't know their interest in me or their language preferences. I could avoid annoying them with German posts by writing in English all the time when doing public posts – but that's a crappy workaround (one I suppose might annoy some of my German friends over time) and not a real solution for the underlying problem.

Yes, you are of course right, that is a problem on Twitter as well. But I solved that easily by using multiple accounts right from the start, which is not easy with G+. Using three accounts also mostly circumvents the problem I indicated in the beginning: Different people are interested in different things and only they can decide what they are interested in.

Here is how I do it with twitter:
  • My main account is @thleemhuis. Just like everybody else I use it to tweet things from my real life (including work). Most of the tweets are German, some are English; almost all of the followers are from Germany or understand German afaics
  • I use @kernellogauthor to tweet about things in the Linux kernel area I stumble upon; it is a kind of bonus and an additional communication channel for readers of my Kernel-Log (DE, EN). Almost all tweets are English (I assume most Germans that read the Kernel Log know English well enough) and kernel related. It has 266 subscribers (some more on identi.ca) and only a handful of them follow @thleemhuis as well
  • Many English speaking people also know me from all the contributions I did to Fedora in the past few years (I'm mostly inactive in that area right now); I follow them via @knurd666 and provide them with a English tweet there now and then; only a handful of them follow @thleemhuis or @kernellogauthor
IOW: I have three kinds of followers (something like 500 on twitter in total and 200 more on identi.ca) that seems to be interested in stuff I do, but there are only very few people (I assume less than 5) that follow all three accounts; and yes, I occasionally mention the different accounts on each other, so it's not a secret I use multiple accounts...

I'd really like to feed them with information from my life or work via Google+, too, but I can not see how to do that efficiently, because right now I have to know that people are interested in; on twitter those that follow me can decide on their own. That's why G+ seems so alien and wrong to me. Something like predefined tags, streams or "outgoing circles" people could select when they add me could help. But maybe that's to complicated; and maybe my situation is special and shows a problem other do not encounter.

P.S.: Yes, maybe I'm thinking to much as someone that wants to maximize the group of people he can reach
-- maybe that has something to do with my day ob ;-)

Donnerstag, 30. September 2010

New Intel graphics drivers released

The Fedora developers among you will be aware: there is a Fedora Test Day with a focus on the Intel graphics card driver today (Thursday the 30th). The X.org driver that is being tested afaics is xorg-x11-drv-intel (also known as xf86-video-intel) version 2.12.0, release 6.fc14 -- the latest F14 build as of today.

Oh, and something else happened today: After three months of development Carl Worth released a xf86-video-intel version 2.13.0. Quoting the release announcement: "[...] With the many bug fixes in this release, we encourage everyone using 2.12 to upgrade to 2.13. [...]"

So people that participate in the testing today might run into bugs that that are fixed in 2.13 or in its pre-release already. But what is even worse from my point of view: With the new and recently ratified Fedora updates policy it seems unlikely to me that Fedora 14 will update to 2.13 ever (note: unlikely still means it's possible!).

My head simply fails to understand why that is the right thing to do in this and similar cases. Even worse: lot's of other distributions have similar policies, so it's take months or years till the fixes the Intel developers worked out in the past three months make their way to regular end users.

Samstag, 5. Juni 2010

Visiting LinuxTag and Red Hat Summit 2010

Blog entry for my fellow readers that visit LinuxTag (next week) or Red Hat Summit/JBoss World 2010 (starting in two and a half weeks from now):
  • I'm in Berlin for LinuxTag next Saturday (on my own efforts).
  • I'm in Boston for the whole Summit to report about it for my employer.
So if you want to meet me in real life simply look out for me or sent a mail to arrange a meeting.

BTW, looks like I might stay in Boston till Sunday afternoon, so I will have some free time once the Summit is over and all work done. Please let me know if you have any good suggestion how to best spent that time it in Boston! tia!

Mittwoch, 11. November 2009

What questions would you like to ask the Candidates for the Fedora Board, FESCo, and FAMSCO?

As you may have heard already, several seats of the Fedora Board, FESCo, and FAMSCO are up for election soon(¹). Right now we are in the nomination period, which will be followed by a "Candidate Questionnaire." That means we'll give candidates a list of questions to answer by private mail within one week after the nomination period closed; the results will be publish soon after that to make sure they are available to the public before the Town Hall meetings on IRC happen.

Candidates may choose to answer (or not) those questions as they see fit. Voters can use the answers to get an impression of what the candidate think or plan to do while serving for the committees they are nominated for. That should help to get a interesting discussion running during the IRC Town Hall meetings; furthermore, those people that can't or don't want to participate in the IRC meetings can use the answers to make a more informed vote.

Hence we need to prepare a few good questions that we can send to the candidates once the nomination period ends. And that's where I need *your help* now:

If you have one or more questions you'd like to send to the candidates simply go and add them to:


It just takes a minute or two, so best to do it right now -- otherwise you might get distracted and forget about it. ;-)

I'll take care of the remaining work to review, sort, and clean up the questions(²); after that I'll send them to the candidates soon after the nomination period ended. Hence, I need your question suggestions by around the 15th November 17:00 UTC latest to get a chance to prepare everything in time.

So please go to the wiki now and add at least one hard question! The answers will help Fedora contributors to chose whom to vote for! Thanks in advance for your help .


(¹) If you haven't read about it yet see
https://fedoraproject.org/wiki/Elections for details.

(²) If you want to get involved or review the questions before I send them please drop me a line and I'll try to get that arranged; maybe we can arrange a quick, informal IRC meeting on Sunday evening if there is interest

P.S.: This blog post is mainly meant to get spread via planet.fedoraproject.org ;-)

Sonntag, 1. November 2009

New RPM Fusion packages: nvidia drivers for F12, staging drivers for F11 and F12

Just FYI:
  • the nvidia graphics drivers finally showed up again in the RPM Fusion repository for rawhide (the current public rawhide to be precise, e.g. what becomes Fedora 12 soon)
  • Most drivers from the linux-staging tree are disabled in the kernels that Fedora ships (among them a few wifi drivers like rtl8187se) . That's a good thing, as they are often of highly questionable quality (¹, ²). But some people nevertheless what them, as they own hardware that needs them(³). Those people from now on can get them easily for Fedora 11 and Rawhide/Fedora 12 by installing kmod-staging from RPM Fusion.
    Please note that:

    • the drivers for Fedora 11 are in rpmfusion-free-updates-testing currently and build for the kernel that is in Fedora's updates-testing repo; thus to use them you need to run something like "yum --enablerepo='*testing' install kmod-staging" and reboot into the kernel that is installed to use them
    • you need to install kmod-staging-PAE if you use a PAE kernel on your x86-32 machine
    • there are no akmod-staging package at this time
    • the package doesn't contain all the drivers from the staging tree; in case you miss one just file a bug in bugzilla.rpmfusion.org and tell the packager to enable it
Also note that it might take some hours till the mirror yum chooses for you offers the packages, as they were uploaded to the master repo just a few minutes before this blog posting got published.

We thank you for your attention and we wish you a pleasant flight.

(¹) that's the long story short

(²) don't expect the drivers to work well; NetworkManager for example will in have problems with some of the WiFi drivers in staging-kmod. In most cases that will be the fault of the driver and not NetworkManager, thus filing NetworkManager bugs that occur with staging drivers is likely a waste of your time.

(³) friends don't let friends buy hardware which need's staging (or even worse: proprietary) drivers on Linux

Samstag, 27. Juni 2009

Presentations from LinuxTag / Fudcon Berlin 2009 available; Tomorrow: Hackfests

My presentations on LinuxTag and Fudcon Berlin 2009 went mostly well. Biggest problem when looking back now: Seems it was more then enough stuff to talk for 90 or 100 minutes, but I only had a hour in total :-/.

Want to look at the slides? Follow these links:
Another problem: There are so many people here at FUDCon and I more and more get the impression that the list with people I "want to meet, shake hands with and talk to for a while, to get a better connection between faces, email addresses, nicks, and (those sometimes overrated) real names" isn't getting shorter as fast as it should to meet everyone in the remaining time. Seems I need to speed up somehow...

It's the same for you? If yes and if you ever wanted to talk to the crazy troublemaker that did or does a lot of work for Fedora, EPEL and Livna/RPM Fusion then just grab me and start to talk to me when you see me walking by or sitting somewhere. The photo on the right shows how I look like, just imagine some mostly inconspicuous glasses on the nose. Ohh, and the hair is a bit shorter right now (I guess nature will do it's best to fix that over time).

BTW, again some informations for the FUDConners: I plan a small "RPM Fusion" hackfest for tomorrow *if* people are interested in one. There is no real plan what to do exactly besides the general idea: Do some work to improve RPM Fusion, and work out the details on the fly. Want to join? Then just watch the wiki and the usual places at FUDCon for details!